Hello
I was wondering if i have well understand the behaviour of 2 smartsolar 100/20 and a smartshunt in a ve network.
the charging current will be sense by the smartshunt, right?
If the charging current is set to 10A in both smartsolar with adéquate battery config, does the smartsolar will be able to absorb the load connected to the battery and charging the battery with 10A ( if enough sun is available)?
I suppose it would be, in the range of 20A all together ( 10A for each smartsolar, regarding the preset current limit), right ?
The behaviour i would like would be : when connected to the ve network, the 2 smartsolar could give full power in limit of their ability ( here 20A each) in respect of the 10A charging current sensed by the smartshunt but it’s not what i understand.
Another thing. Without smartshunt or equivalent in the ve network, the charging current is calculated by summing all charging current of all the smartsolar. Does the load output current of each smartsolar are involved ? With 2 smartsolar 100/20 limited to 10A charging, load output 8A on smartsolar n°1, load output 1A on smartsolar n°2, enough sun, the battery current will be 10A or 1A?
Same question with load of 15 A on the smartsolar n°1 load output and 1A on the n°2 load output, the effective current going to the battery will be 4A? Or draining 6A?
My battery bank is now just a 100ah 24v bank wet lead. After 15 years in offgrid, i prefer to direct consum power than stacking it. power from battery is just for ligths, phones or computer. This method have Really better efficiancy ( only charging discharching from a battery is approximative 20 to 30% loss in real life, depending of the all system), really better expectancy life of all coponants, more safety, … I can go further and further but this will just lead keyboard warriors with a cousin, or a “bunch of friend” (or someone else who think he’s smart because he thanks he know google better than anyone) to make this post annoying and i will just loose the possibility to have answer to my questions.
Thanks for the comment but i don’t think you understood my question, please read the post, and try to not repeat the unclear description of the behaviour that i have already stated after reading a “bunch” of victron’s docs.
You want to set the MPPTs to 10A each to charge your battery with max. 20A.
But you also want to supply your load from PV as much as possible.
But with that settings you will only get 20A of PV and if you have a 30A load you will discharge the battery even if you would have more PV power available.
Each MPPT will give you max 10A no matter if/what loads are running.
What you need it DVCC.
With DVCC you can configure a max charging current but still use the full power of your PV panels if you have a bigger load running.
If that is not what you want than please try to rephrase your question.
Again, no, please read the first post (100ah battery leaded=10a current max)!
10, not 20!
But in a ve network, 2 smartsolar can do that. I think it’s the main goal of the ve network.
And why 2 solar regulator ? Redondancy.
Ok than it’s 10A but doesn’t change the answer:
It doesn’t work that way.
If you set each MPPT to 10A and you have no loads than your battery will be charged with 20A.
If you have 10A load your battery gets 10A.
If you have 20A load your battery gets 0A.
If you have 30A load your battery gets discharged with 10A
As such, it is not possible to configure a ‘network-wide’ maximum charge current. In case such feature is needed, for example in a system with both an East- and a West-facing PV array and relatively small battery bank, consider using a GX Device and its DVCC features.
No, not with the ve network, like mentioned in the original post. It will be 10A, read the full doc you gave the link, it’s just above. Once linked, they behave like one charger. And if you don’t believe the victron’s doc, try it in real life.
Please, can you go aside and let someone with theorical and pratical skills shime in?
I will try to be more clear in my several questions
1)in a case of
Right or wrong?
If Right, this would make suppose the smartsolars will compensate the load until reaching their capability to do so set by the charging current limit. But it could be otherwise, that’s why i ask for advice.
If Wrong, What’s the point to integrate
the smartshunt in the ve network ? Only to sense charging tail current ?
2)in a case of 2 smartsolar 100/20 in ve network without smartshunt and enough sun
10A charging current limit
2a)What is the expected behaviour of the load output of the smartsolars?
2b) what is the expected battery charging current with 8A drain from the output load of smartsolar n°1 and 1A drain from smartsolar n°2?
2c) what is the expected battery charging current with 15A drain from the output load of smartsolar n°1 and 1A drain from smartsolar n°2?
The network only synchronizes the charging algorithm, not the current.
Each MPPT will change with its configured current.
Each unit will (and should) regulate its own output current. Which, among others, depends on the output of each PV array, cable resistance and the configured maximum output current of the charger.
As mentioned before, battery charge current is not controlled by the master, but by each of the chargers individually.
For the second part of your question I already gave you some examples.
The load output is working on it’s own, no matter if/how much current the MPPT is producing.
Charging current - load current = current into/out of the battery.
10A charging from MPPT 1 + 10A charging from MPPT 2 - 8A load current at MPPT 1 - 1A load current at MPPT 2 = 11A for the battery
10A charging from MPPT 1 + 10A charging from MPPT 2 - 15A load current at MPPT 1 - 1A load current at MPPT 2 = 4A for the battery
Ok thanks, first question answered. The smartshunt is not used to sense current during the most part of the charge. What a shame.
Ok then, IMO, the smartshunt is completly irrelevant for small system with short length of wire, just a potential failure point added.
For the point 2 question:
In the doc, same link provided by you earlier, it is said “Connect multiple SmartSolar charge controllers together in a VE.Smart network to make them charge the battery as if they were one large charger.”
I assume you’ve read this correctly
It’s not 10A charging, it’s the current limit set in the smartsolars. charging current could be 10A maximum.
Who’s wrong ? You or the doc? One large charger set to 10A can’t charge at 11A if working properly.
And if you’re right (and this part of the doc wrong), this would be really worst than i could ever think, making just irrelevant the existence of the ve network itself.
This would mean i would have to set the charging current limit to 5A on each smartsolar, meaning if one PV string is shaded or disfonctionnal, it will not be able to achieve a 10A charging current with a full exposed and working 500wp. It would be so stupid to develop a network for such a poor behaviour at the end that i can’t imagine you are right.
but because there is a possibility you are, i’m going to make a real conditions test. Less talking, more action.
I will be so mad at victron if you’re right
They ACT like one charger, they synchronize the algorithm (switching from bulk to absorption together) but they are still two individual devices.
As I already wrote a few times:
If you set both to 10A you get 20A of current (if all panels are in full sun).
If you want a max total of 10A you have to configure each MPPT to 5A.
And yes, that way you loose a lot of PV power.
The current measured by the shunt is only used for the tail current, as it is described in the manual.
(The shunt will also calculate and show the SOC of the battery)
Only with a GX device and DVCC you can achieve what you want.
You set each MPPT to 20A and in DVCC you can limit the charging current to 10A.
The GX device will then control the MPPTs that only 10A are going into the battery.
If needed the GX device will tell the MPPTs to produce more to compensate for loads while still charging the battery with 10A.
That’s always the best.
If you already have all components that’s the best way to proof me wrong or confirm what I wrote.
If I have some time next week (and we have the components needed laying around) I might will do a test too.